WO2024037694A1

WO2024037694A1 - Braking device for a vehicle with increased operating safety and method for operation

Info

Publication number: WO2024037694A1
Application number: PCT/DE2023/200160
Authority: WO
Inventors: Joseph Dolmaya; Georg Sonnenschein; Marco Müller; Christian Courth; Johannes GÖRLACH
Original assignee: Continental Automotive Technologies GmbH
Priority date: 2022-08-19
Filing date: 2023-08-09
Publication date: 2024-02-22
Also published as: DE102022208623A1

Abstract

The present invention relates in general to a braking device for a vehicle with increased operating safety and to a method for operating a braking device for a vehicle with increased operating safety. The proposed braking device comprises: a container having a cavity; a hydraulic block; and an electronic brake control device, which is designed to control the pressure supply apparatus. The brake control device is disposed in the container. Furthermore, at least one sensor element is provided, which is designed to detect a fluid.

Description

Braking device for a vehicle with increased operational safety and method of operation

The present invention generally relates to a braking device for a vehicle with increased operational safety and a method for operating a braking device for a vehicle with increased operational safety.

Service brake systems for motor vehicles are generally known, in which the wheels on the front or rear axle can be braked using electro-hydraulic or hydraulically actuated wheel brakes.

For this purpose, an electro-hydraulic brake system can, for example, have a hydraulic block, with, among other things, an electromotive pressure supply device being arranged in the hydraulic block, which is connected to a brake fluid container and the hydraulically operated wheel brakes. For a compact design and simple assembly, the required components, for example the pressure supply device and the associated electronic brake control device, can be accommodated in a common module.

A braking request from the vehicle driver is typically detected by a corresponding actuation device with a brake pedal, which is designed to determine an actuation signal that quantifies a braking request as a result of an actuation by a vehicle driver and to pass it on to the brake control unit.

For example, in hydraulically actuated service brake systems, when the brake is actuated, there can be a reaction to the brake pedal, so that the vehicle driver can get a brake pedal feel that depends on the brake pressure on the wheel brakes. In this way, the vehicle driver is connected to the wheel brakes during normal operation. However, if an electric brake pedal, also known as an ePedal, is used as the actuating device, a reaction to the brake pedal in the event of a pressure change is no longer possible via the mechanical or hydraulic connection between the brake pedal and the wheel brake. This can be unfavorable if there are impairments in connection with the service brake, for example as a result of a leak in the area of the brake fluid system.

A leak in the brake fluid system can generally be detected using a brake fluid switch. However, it may also be possible that brake fluid does not escape from the brake system, but instead collects within the brake device. In this way, brake fluid can also get into the module or on or into the associated components. For example, escaping brake fluid can, in the worst case scenario, come into contact with the brake control unit, which can influence the control of the wheel brake.

If the driver is now informed of a loss of brake fluid and, as a result, this possible deficit of brake fluid is simply replenished, this does not eliminate the problem that brake fluid leaking within the braking device can lead to damage. In other words, a leak that occurs within the braking device cannot be reliably detected in this way in certain cases.

In these cases, especially when using an electric brake pedal, the vehicle driver cannot receive any feedback about possible impairments in the functionality of the braking device via the brake pedal. As a result, the vehicle driver no longer has a direct opportunity to detect changes in connection with the service brake system, for example as a result of a leak in the brake fluid reservoir. As a result, the vehicle driver is no longer able to recognize a possible deterioration in the braking system or is not able to recognize it sufficiently quickly. This can be problematic in that such a leak within the braking device could lead to impairments in the braking ability, which would not be detected. This is also unfavorable with regard to partially automated or automated ferry operations >= Level 2.

The present invention is therefore based on the object of specifying a braking device, in particular for a motor vehicle, and a method for operating such a braking device, which does not have the disadvantages mentioned above and thus has increased operational reliability.

It is also desirable to have a braking device that can also be used for partially automated or even automated ferry operations > Level 2.

The inventors have taken on this task.

This task is solved surprisingly simply by a braking device as part of a braking system, in particular for a motor vehicle, and a method for operating a braking device according to one of the independent claims.

Preferred embodiments and further developments of the invention can be found in the respective subclaims, the content of which is made the content of the present description by express reference.

The subject of the invention is therefore, in a first aspect, a braking device as part of a braking system, in particular for a motor vehicle, comprising a container with a cavity, a hydraulic block with a pressure supply device, and an electronic brake control device which is set up to control the pressure supply device, the electronic Brake control unit is arranged in the container, wherein at least one sensor element is provided, which is designed to detect a fluid, and wherein the sensor element is arranged in the container or in the hydraulic block.

The braking device can be part of a service brake, especially for a motor vehicle.

To protect the electronic brake control device, the container is preferably designed to be closed and in this way defines a cavity. The brake control device is arranged at least partially, preferably completely, in the cavity of the container.

The pressure provision device can also be arranged in this container. However, in many cases this is not favorable. In a preferred embodiment, it is therefore provided that the pressure supply device is housed in a so-called hydraulic block and the electronic brake control device is housed in a separate container, whereby the container and the hydraulic block can be firmly connected to one another.

The container for the electronic brake control unit can be attached to the side next to the hydraulic block, but also underneath it, for example for reasons of space. The hydraulic block and the container with the electronic brake control unit, as well as possibly other devices, such as an assigned brake fluid container, can be designed and provided together as a module according to a preferred embodiment of the invention.

This also does not affect the fact that further devices and components for a brake or a wheel brake can be accommodated in the container.

According to the invention, at least one sensor element is provided in the container, which is designed to detect a fluid. The at least one sensor element is preferably on one of the floors during operation indicative place within the container or the hydraulic block in order to be able to detect penetrating fluid as early as possible.

The braking device can include a switching unit for processing signals from the at least one sensor element. The switching unit can also be designed as part of the brake control device or integrated into the brake control device. The brake control device or the switching unit can also include at least one memory unit, for example to store measured values of the sensor element. The sensor element is connected to the electronic brake control unit or to the switching unit, so that the sensor element can be supplied with power and controlled and the switching unit or the brake control unit can receive signals from the sensor.

The fluid may generally comprise a liquid medium. This includes in particular brake fluid, oil, water, coolant, steering fluid or other fluids that occur or may be present in connection with the operation of a vehicle.

The sensor element is designed to recognize or detect the presence or occurrence of a fluid. In other words, the sensor element can detect a fluid and generate a signal that can be transmitted to the electronic brake control unit or the switching unit when the sensor element comes into contact with the fluid. Querying the sensor signal or monitoring the sensor element can take place both cyclically and continuously. Suitable controllers can be provided for this purpose.

According to a preferred embodiment of the invention, the container of the hydraulic block can comprise a floor or a floor area, preferably with a depression, which in the mounted position, in particular in the operating state of the braking device, defines the lowest point of the container. For this purpose, the bottom can advantageously be designed to taper towards the depression. In comparison to a more flat floor area, this can It must be ensured that a fluid in the container collects at a defined point in the sink. A fluid in the container can therefore be detected safely and quickly. Nesting or angulations in the bottom area should be avoided if possible, as these could impair the flow of the fluid towards the depression, so that penetrating fluid may not be detected in time.

In a further development of the invention, at least one bead can additionally be provided in the floor, which is aligned towards the depression. This allows a fluid to be quickly directed to the sink where it can be detected.

In principle, it is not desirable for there to be a fluid in the container or in the hydraulic block during operation, since impairment and/or damage occurs when a fluid comes into contact with the electronic brake control unit, which is typically designed as a circuit board or may include a circuit board can occur in the brake control unit. For example, electronic components can be damaged, which can lead to an impairment of the functionality of the brake. Corrosion can also occur.

The fluid can enter the container with the brake control unit from the outside, for example fluid from the environment as a result of a leak in the container. However, the fluid can also emerge from the hydraulic block and enter the container, for example if the pressure supply device has a leak. The hydraulic block can, for example, include valves from which fluid, in particular brake fluid, can also emerge. In this way, for example, brake fluid can get into the container with the electronic brake control unit.

Preferably, the at least one sensor element is arranged in the bottom area or near the bottom of the container or the hydraulic block in order to be able to quickly detect a possible fluid. It is advantageous to have at least one sensor element in the area of the sink or even, if possible due to the installation space, arranged within the sink in order to be able to detect a fluid quickly and safely.

Instead of a single sensor element, which thus represents a discrete measuring point, according to a further development of the invention, several sensor elements can also be provided, which can be spaced apart from one another in the vertical direction. In this way, several discrete measuring points can be provided, which can detect different heights or fill levels of fluid in the container or the hydraulic block.

In a favorable embodiment of the invention, the container is designed in two parts, with an intermediate wall separating a first and a second partial volume from one another. A part of the cavity of the container is therefore defined as a partial volume. The two-part design makes it possible to provide the brake control device twice, so that these components, which are important for the functioning of the brake, are present twice and thus there is redundancy.

For this purpose, a first electronic brake control device can be arranged in the first and a second electronic brake control device in the second partial volume.

In normal operation, for example, the wheel brake can then be operated in the first partial volume by means of the first electronic brake control device. In the event of impairment or failure of the first brake control device in the first partial volume, a switch can then be made to the second brake control device in the second partial volume. For this purpose, it is advantageous to design the intermediate wall to be fluid-tight, as far as technically possible, so that the second partial volume of the container is protected from the penetration of fluid into the first partial volume.

According to a preferred embodiment of the invention, the brake control device comprises at least one printed circuit board (PCB), wherein the sensor element is formed on the circuit board or as part of the circuit board. This enables particularly simple and cost-effective production and assembly.

The at least one sensor element is preferably arranged on a section of the circuit board that faces the ground during operation. In a preferred embodiment, this section of the circuit board that faces the ground during operation is free of other electronic or other components, so that the sensor element essentially represents the lowest-lying component of the circuit board in normal operation. The section pointing towards the floor therefore means an area of the circuit board which adjoins the lower edge of the edge of the circuit board pointing towards the floor. In this way, an entry of fluid can be detected particularly favorably by the sensor element before other components can come into contact with incoming fluid.

According to a further development of the invention, the circuit board can also comprise a projecting area or projection on the edge that points towards the ground during operation. The at least one sensor element can then advantageously be placed on this projection. In this way, the area of the circuit board can be used particularly favorably for the required components, and layout plans can be adopted without major changes or do not have to be changed in order to be able to place the sensor element.

Advantageously, the projection is geometrically or structurally adapted to the depression in the bottom area of the container. This makes it possible to arrange the projection with the sensor element in the depression at least in sections.

However, the sensor element can also be designed as a separate component according to a further embodiment. This allows greater flexibility in the layout of the sink and PCB.

In a preferred embodiment of the invention, the at least one sensor element is designed as a conductivity sensor. For this purpose, according to one embodiment, two conductor tracks can be placed on the circuit board at a short distance to each other, for example one or a few millimeters, which are electrically contacted and subjected to an electrical voltage. Upon contact with the fluid, an electrical connection can be established between the two conductors and an electrical short circuit can be generated, which can be detected by the switching unit or the brake control unit. In other words, the electrical contacting of the two conductors is galvanically separated from one another by an insulation path, whereby this insulation path can be bridged by the fluid. A measured value of an electrical quantity resulting between the electrical contacts can be recorded.

With at least one sensor element or a discrete measuring point, the switching unit can thus receive a signal or information that a fluid is present at the measuring point. This can indicate, for example, that brake fluid has penetrated into the depression of the container or the hydraulic block. If there are several sensor elements or several discrete measuring points, information about the height of the fluid level can also be obtained. In this way, a leak rate can also be determined.

The switching unit or the electronic brake control device is preferably set up to process this information and to initiate corresponding actions based on stored error data or protocols and using decision logic. These can, for example, include warnings to the driver. Accordingly, a device for generating and issuing information or warning to the vehicle driver can also be included.

For example, warning lights in the driver's field of vision can light up yellow or red to indicate the danger and the degree of impairment.

The invention thus ensures that in the event of a sudden leak, for example due to a leak in a sealing ring due to wear or Material fatigue can be recognized quickly and appropriate countermeasures can be initiated.

In a further development of the invention it is also provided to influence the control and regulation of the brake system. This can be done, for example, by switching the second brake control device active instead of the first brake control device, which can be affected by the penetration of fluid into the first partial volume, and thus using it to control the wheel brake. At this point it should be noted that within the scope of the present invention no distinction is made between the terms “control” and “regulate”. The meaning of the corresponding terms arises from the respective context.

In a further development of the invention, it is also considered to end the ferry operation according to a predetermined program if a critical value is exceeded or fallen below, for example in an autonomous ferry operation.

In this way, a fallback level can be created particularly easily in the event of a leak in the braking device, for example a leaky pressure supply device.

For this purpose, it may be sufficient if, in the case of a two-part design of the container, the at least one sensor element is arranged solely in the first partial volume in which the brake control device is housed for normal operation. When a fluid is detected in this partial volume, it can be switched to the brake control device in the second partial volume, and operation of the wheel brake in a fallback level as emergency operation can be maintained.

Since the intermediate wall, which separates the two partial volumes from one another, often cannot be made fluid-tight, for example as a result of wiring through the intermediate wall, according to a preferred embodiment of the invention, a sensor element is provided in each case to arrange the first and second partial volumes. In this way, information about penetrating fluid can be generated in both partial volumes. This is advantageous because fluid can penetrate into both partial volumes at the same time and the functionality of the braking device can therefore still be monitored.

For example, if sensor elements in both partial volumes detect fluid penetration, a red warning light can signal to the vehicle driver that the braking device is defective and it is not possible to continue driving. This can ensure further increased safety, which is particularly advantageous with regard to partially automated or fully automated driving.

The above-mentioned conductivity sensor represents only one possible embodiment of a sensor element. Other embodiments of the sensor element are also envisaged and provided within the meaning of the invention.

According to a further, also preferred embodiment of the invention, a sensor element is provided which comprises a fluid-sensitive element. The fluid-sensitive element can comprise a material which, in conjunction with fluid, changes at least one property, for example volume or electrical conductivity.

In a first embodiment of this embodiment it is provided that the element comprises a material which expands upon contact with the fluid and thus increases its volume. The expansion can exert a force on a pressure sensor, which can be detected. The change in volume can thus be detected by means of the pressure sensor, which can then send a corresponding signal to the switching unit. The swelling material may comprise a hydrophilic polymer material, such as rubber.

In a second embodiment it is provided that the element comprises a material which shrinks or even dissolves through contact with the fluid. For this purpose, a material that is electrically conductive can advantageously be selected. This Material can be placed between two electrical conductors. If this material shrinks or even dissolves upon contact with the fluid, the electrical connection is interrupted and the switching unit receives a corresponding signal. A suitable material may include a thermoplastic, in particular polyvinyl alcohol (PVA), which can dissolve upon contact with fluid. This effect can be used to interrupt electrical contact.

In a further development, a hygroscopic material is also provided which, upon contact with a fluid, can absorb it and thereby change its properties, in particular its electrical conductivity. The electrical resistance can be measured continuously by means of the brake control device, so that a change in the electrical conductivity can be recognized and in this way an incoming fluid can be detected.

According to a further, also preferred embodiment of the invention, a sensor element is provided which comprises a floating body, the floating body being arranged to be movable in the vertical direction. When a certain position is reached or when a predetermined position is left, a corresponding electrical signal can be sent to the switching unit, for example by the floating body triggering a microswitch at a certain position. The use of reed switches or reed sensors in combination with permanent magnets is also considered and possible. The floating body can be arranged, for example, in the hydraulic block.

According to a further, also preferred embodiment of the invention, a sensor element is provided which is designed as an optical liquid sensor, comprising an emitter which can emit electromagnetic radiation and a light sensor which is designed to detect this electromagnetic radiation. The emitter can include, for example, a light-emitting diode or a laser source. The light sensor can include, for example, CMOS or CCD sensors. In a first embodiment of this embodiment it is provided that the emitter emits the electromagnetic radiation directly in the direction of the light sensor. In other words, the light sensor is in the main beam direction of the emitter. It is advantageous for the emitter and light sensor to be arranged at a certain distance from one another so that fluid can get between the emitter and the light sensor.

When a fluid penetrates the space between the emitter and the light sensor, the electromagnetic radiation can be attenuated by optical effects, for example by light scattering. This attenuation can be detected by the light sensor and given as a corresponding signal to the switching unit.

However, it is also possible to arrange the emitter in the first partial volume, for example on a circuit board of the first electronic brake control device, and the light sensor in the second partial volume, for example on the second circuit board of the second electronic brake control device, and to pass the radiation through a continuous opening pass through the hydraulic block. A through hole can be used particularly advantageously for this purpose, for example, which serves to wire the two electronic brake control devices. In this way, an emitter and a sensor element do not have to be arranged in each of the two partial volumes, so that this arrangement can be carried out more cost-effectively. It goes without saying that the emitter, light sensor and continuous opening are arranged as close to the ground as possible. If the through hole is designed appropriately, fluid escaping from the hydraulic block can be detected very quickly, especially before the circuit boards can be damaged.

In a further embodiment of this embodiment it is provided that the emitter directs the electromagnetic radiation towards a reflecting element, for example a mirror. During normal operation, this reflective element can reflect the incoming radiation and redirect it in the direction of the light sensor. The reflective element is advantageously inclined for this purpose opposite the beam direction of the emitter. The mirror can be made very small, so that it can be easily arranged at the bottom of the container or, if available, in the depression. According to a further form of training, the depression can also have a reflective surface, which in this respect represents the reflective element. As soon as fluid penetrates, at least part of the electromagnetic radiation is diffusely reflected on the surface of the fluid, so that an attenuation also occurs on the light sensor, which can be detected. This design can also be implemented cost-effectively and is highly flexible, since the reflective element can be arranged at the lowest point of the container without contacting.

Included in the invention in a further aspect of the invention is a method for operating a braking system for vehicles, in particular a service braking system, comprising at least one braking device as stated above.

Included in the invention, in yet another aspect of the invention, is a braking system, in particular a service braking system, for a vehicle, comprising at least one braking device as stated above. The braking system can be used to control a wheel, or to control the wheels of an axle or even for all wheels.

The present invention therefore provides a braking device, in particular for a motor vehicle, and a method for operating such a braking system, which has increased operational reliability.

The invention thus also provides a braking system for partially automated or automated ferry operations, in particular level 2 according to SAE J3016 or above.

Further details of the invention emerge from the description of the exemplary embodiments shown and the appended claims. The drawings show:

1 is a schematic representation of a circuit diagram of an exemplary braking device,

2a is a schematic representation of an exemplary brake device with a possible arrangement of a hydraulic block and a container for accommodating an electronic brake control device,

2b is a schematic representation of an exemplary brake device with a further possible arrangement of a hydraulic block and a container for accommodating an electronic brake control device,

3a shows a schematic representation of a section of a circuit board with a conductivity sensor,

3b is a schematic representation of a section of a circuit board with two conductivity sensors,

4a shows a schematic representation of a fluid-sensitive element with a pressure sensor,

4b is a schematic representation of a fluid-sensitive element with electrical contacting,

5 shows a schematic representation of a sensor element with a floating body,

6a shows a schematic representation of a sensor element with an optical liquid sensor according to a first exemplary embodiment, 6b shows a schematic representation of a sensor element with an optical liquid sensor according to a second exemplary embodiment, and

6c shows a schematic representation of a sensor element with an optical liquid sensor according to the second exemplary embodiment with fluid.

In the following detailed description of preferred embodiments, for the sake of clarity, like reference numerals designate substantially like parts in or on these embodiments. However, to better illustrate the invention, the preferred embodiments shown in the figures are not always drawn to scale.

Fig. 1 shows a circuit diagram of an exemplary electro-hydraulic brake device 100. The brake device 100 has a hydraulic block 200, wherein in the hydraulic block 200 there is an electromotive pressure supply device 202 with a motor position sensor 214, a pressure switching valve 206, two pressure sensors 212 and an inlet valve 216 for each wheel brake an exhaust valve 218 are arranged as essential components of a brake system.

The hydraulic block 200 is connected to a brake fluid container 110 and the hydraulically operated wheel brakes 208.

The electromotive pressure supply device 202 is hydraulically connected to the wheel brakes 208. The pressure sensor 212 and a normally open inlet valve 216 for each wheel brake 208 are arranged between the pressure switching valve 206 and the wheel brakes 208. The inlet valves 216 are preferably designed as analogized solenoid valves for modulating a pressure generated by the pressure supply device 202. The wheel brakes 208 are in turn connected to the brake fluid container 110 via the outlet valves 218, the outlet valves 218 being designed as normally closed valves. Finally, the wheel brakes 208 are connected to the brake fluid container 110 on the inlet side.

During normal operation of the brake device 100 shown, the pressure switching valve 206 is open, so that there is a direct hydraulic connection between the pressure supply device 202 and the wheel brakes 208. The hydraulic pressure provided by the pressure supply device 202 based on an actuation signal can then be individually modulated by the inlet valves 216 and the outlet valves 218 for the wheel brakes 208, whereby in particular ABS control functions can be implemented. The pressure provision device 202 is preferably controlled based on a signal from the motor position sensor 214.

2a shows a schematic representation of an exemplary brake device 100 with a possible arrangement of a hydraulic block 200 and a container 300 for accommodating an electronic brake control device 311, 321. In this arrangement, the container 300 is arranged essentially below the hydraulic block 200. The container 300 can be flanged to the hydraulic block 200. In this space-saving embodiment, the brake fluid container 110 (not shown in these FIGS. 2a and 2b) can be arranged above the hydraulic block 200, opposite the container 300.

2b shows a schematic representation of an exemplary brake device 100 with a further possible arrangement of a hydraulic block 200 and a container 300 for accommodating an electronic brake control device 311, 321. In this exemplary embodiment, two containers 300 are provided, which are located essentially on both sides of the hydraulic block 200.

The container 300 is designed as a closed housing to protect the electronic brake control devices 311, 321. It will be apparent to the person skilled in the art that these two embodiments only show possible arrangement variants of the container 300 and that further arrangements are also possible and considered.

The container 300 shown schematically in FIG. 2a is designed with two partial volumes 312, 322, with an electronic brake control device 311, 321 being arranged in each partial volume 312, 322. The two partial volumes 312, 322 are separated from one another by an intermediate wall 301.

The electromotive pressure supply device 202 can be driven, for example, by a brushless electric motor, which can be controlled by each of the two electronic brake control devices 311, 321.

Furthermore, two sensor elements 400 are arranged in the container 300, which are designed to detect a fluid. In Figures 2a and 2b, these sensor elements 400 are shown only schematically for illustrative purposes. The sensor elements 400 are each connected to the assigned brake control unit 311, 321.

The fluid may generally comprise a liquid medium. This includes in particular brake fluid, oil, water, coolant, steering fluid or other fluids. From Figures 2a and 2b it can be seen that in the event of a leak in the hydraulic system 200, for example a leak in the pressure supply device 202 or a valve 206, 216, 218, brake fluid enters the hydraulic block 200 and from there into the container 300 via openings can, for example through openings for electrical contacting.

According to a preferred embodiment of the invention, the container 300 or the hydraulic block 200 comprise a bottom 302 with a depression (not shown), which is the lowest point in the assembled position or during operation Are defined. The bottom is also advantageously designed to taper towards the depression. Compared to a more flat floor, this can ensure that a fluid collects at a defined point in the depression. A fluid penetrating into the container 300 can thus be detected safely and quickly. Nesting or angulations in the floor area should be avoided if possible, as these could affect the flow of the fluid towards the sink.

The presence of a sink is not mandatory. Of course, it is also possible to make the floor 302 flat, as shown in Figures 2a and 2b, or, for example, oblique or inclined.

In a further development of the invention, at least one bead can additionally be provided in the base 302, which is aligned towards the depression. This allows a fluid to be quickly directed to the sink where it can be detected.

In order to protect the electronic brake control device 311, 321 in the container 300, it is advantageous if there is no fluid in the container 300, since if a fluid comes into contact with the electronic brake control device 311, 321, this will cause impairment and/or damage to it electronic brake control unit 311, 321 can come.

The sensor elements 400 are arranged near the ground in order to be able to quickly detect possible fluid. Advantageously, the at least one sensor element 400 is arranged in the area of the depression or even, if possible due to the installation space, within the depression in order to be able to detect a fluid quickly and reliably.

In the example of FIG. 2a, a sensor element 400 is provided in each partial volume 312, 322.

Instead of a single sensor element 400, which thus represents a discrete measuring point, according to a further development of the invention several sensor elements 400 may be provided, which can be spaced apart from one another in the vertical direction. In this way, several discrete measuring points can be provided, which can detect different fill levels of fluid in the container 300.

The sensor element(s) 400 are connected to the electronic brake control unit 311, 321 or to the switching unit, so that the switching unit or the brake control unit 311, 321 can receive signals from the sensor element 400.

The intermediate wall 301 allows the brake device 100 to be designed redundantly, so that if one electronic brake control device 311, 321 fails or is impaired, it is possible to switch to the other electronic brake control device 311, 321.

The electronic brake control device comprises at least one circuit board 500, with the sensor element 400 on the circuit board 500 or as part of the circuit board

500 is trained. 3a shows a schematic representation of a section of a circuit board 500 with a conductivity sensor 510 of a brake control device 311, 321. The circuit board 500 is equipped with a sensor element, marked in its entirety with the reference number 400, on a corner of the circuit board 500.

The sensor element 400 is on the section pointing towards the ground during operation

501 of the circuit board, which should be indicated by the dashed line 503. The section of the printed circuit board 500 shown points towards the floor in the assembled position. In the illustrated embodiment, the lower section 501 is free of other electronic or other components 502, so that the sensor element 400 represents the lowest component of the circuit board 500. In this way, an entry of fluid can already be detected by the sensor element 400 before other components 502 can come into contact with incoming fluid. According to a further development of the invention, the circuit board 500 can also include a projecting area or projection (not shown) on the edge that points towards the ground during operation. The at least one sensor element 400 can then advantageously be placed on this projection. In this way, the area of the circuit board can be used particularly favorably for the required components, and layout plans can be adopted without major changes or do not have to be changed in order to be able to place the sensor element. In a favorable embodiment, the projection is geometrically or structurally adapted to the depression in the bottom area of the container 300. This makes it possible to arrange the projection with the sensor element 400 in the depression at least in sections.

However, the sensor element 400 can also be designed as a separate component according to a further embodiment. This allows greater flexibility with respect to the placement of the sink and circuit board 500, for example if the circuit board 500 is to be located at a location other than a sink.

In the embodiment shown in FIG. 3a, the sensor element 400 is designed as a conductivity sensor 510. For this purpose, two conductor tracks 511, 512 are arranged on the circuit board 500 at a short distance from one another, for example approximately 1 mm. The conductor tracks 511, 512 are electrically contacted via contacts 514 and subjected to a voltage.

Upon contact with the fluid, an electrical connection can be established between the two conductors 511, 512, which can be recognized by the switching unit or the brake control device 311, 321.

With only one sensor element 400 or a discrete measuring point, the switching unit can thus receive a signal or information that a fluid is present at this measuring point and has therefore penetrated into the container 300.

With multiple sensor elements 400 or multiple discrete measuring points, information about the height of the fluid level can also be obtained. On In this way, a leak rate can also be determined, i.e. an increase in fluid over time.

3b shows, purely as an example, a schematic representation of a section of a circuit board with two sensor elements 400, which in the example are also designed as conductivity sensors 510 as shown in FIG. 3a.

Of course, it is also possible and considered to arrange more than two sensor elements 400 at different heights, for example three, four or five sensor elements 400.

Of course, it is also possible to provide other embodiments of sensor elements 400, as explained, for example, further below. It is also possible and considered to combine different embodiments of sensor elements 400 with one another.

Conductivity sensors 510 as shown in FIGS. 3a and 3b are comparatively simple and inexpensive to implement. They can also be very small, which also speaks for their use.

As shown in Fig. 2a, it is advantageous if at least one sensor element 400 is provided in each of the two partial volumes 312, 322. This is due to the fact that the intermediate wall 301 often cannot be made completely fluid-tight, for example as a result of wiring through the intermediate wall 301. In this way it can be ensured that fluid can be detected in both partial volumes and the corresponding reactions can be triggered.

Further suitable embodiments of sensor elements 400 are shown in FIGS. 4a and 4b using the example of a fluid-sensitive element 600. The fluid-sensitive element 600 is designed to change at least one property upon contact with a fluid. This property affects the 4a and 4b, the volume of the fluid-sensitive element 600.

4a shows a schematic representation of a fluid-sensitive element 600 with a pressure sensor 620, wherein the fluid-sensitive element 600 is designed to increase its volume upon contact with a fluid. In the example, the fluid-sensitive element 600 includes a swelling material, in particular a hydrophilic polymer material, for example rubber.

Upon contact with the fluid, the fluid-sensitive element 600 expands, which can be detected with the pressure sensor 620. The pressure sensor is connected to the switching unit or the brake control unit 311, 321 via electrical conductors 611, 612 in order to give a corresponding signal to the switching unit or the brake control unit 311, 321.

4b shows a schematic representation of a fluid-sensitive element 600 of a further embodiment with electrical contacting. According to this embodiment, the fluid-sensitive element 600 comprises a material that shrinks or even dissolves upon contact with the fluid. The material is electrically conductive and is arranged between two electrical conductors or electrical contacts 614. Upon contact with the fluid, the material can shrink, causing the electrical connection to be interrupted and a corresponding signal to be emitted. In the example, the fluid-sensitive element 600 comprises polyvinyl alcohol (PVA), which dissolves upon contact with fluid and thereby interrupts an electrical connection.

According to a further development of this embodiment, a hygroscopic material can also be used, which can absorb fluid from the environment and thereby change its properties, in particular its electrical resistance.

Embodiments with a fluid-sensitive element 600 can be used particularly flexibly because they can be made correspondingly small and are therefore particularly suitable for being arranged in a depression or another lowest point of the container 300.

According to a further, also preferred embodiment of the invention, a sensor element 400 is provided, which comprises a floating body 700, wherein the floating body 700 is arranged to be movable in the vertical direction. When a certain position is reached or when a predetermined position is left, a corresponding electrical signal can be sent to the switching unit, for example by the floating body 700 triggering a microswitch at a certain position. The at least one floating body 700 can be arranged in the hydraulic block 200 according to an embodiment of the invention.

5 shows an example of a schematic representation of such a sensor element 400 with a floating body 700, which is arranged on a guide 701. The guide 701 enables vertical guidance of the floating body 700. The floating body 700 is housed in a leakage chamber 703, which represents the sink of the arrangement. For this purpose, bores 702 are provided in the exemplary embodiment through which fluid can flow to the sink. In the exemplary embodiment, the float 700 and the sink are arranged in the hydraulic block 200 to save space, although other arrangements are of course also possible and conceivable. As soon as fluid flows into the sink, the floating body 700 rises and can trigger a switch, for example a microswitch, whereupon a corresponding signal can be given via the conductors 711 to the circuit boards 500 of the two electronic brake control devices 311, 321.

According to a further, also preferred embodiment of the invention, a sensor element 400 is provided, which is designed as an optical liquid sensor, comprising an emitter 800, which can emit electromagnetic radiation and a light sensor 801, which is designed to detect this electromagnetic radiation. The emitter 800 may include, for example, a light-emitting diode or a laser source. The light sensor 801 may include, for example, CMOS or CCD sensors.

6a shows a schematic representation of a sensor element 400 with such an optical liquid sensor according to a first exemplary embodiment. In the exemplary embodiment it is provided that the emitter 800 emits the electromagnetic radiation directly in the direction of the light sensor 801. The electromagnetic radiation, for example in the visible wavelength range, is shown in the figure with arrows only as an example and marked with the reference number 811.

If a fluid penetrates into the space between emitter 800 and light sensor 801, electromagnetic radiation 811 can be attenuated by, for example, light scattering. This attenuation can be detected by the light sensor 801 and given as a corresponding signal to the switching unit.

In the exemplary embodiment, the emitter 800 is arranged on the circuit board 500 of the first electronic brake control device 511 and the light sensor 801 on the circuit board 500 of the second electronic brake control device 521, which represents a particularly cost-effective embodiment. The electromagnetic radiation 811 is passed through the hydraulic block 200 through a through opening 812. Emitter 800, light sensor 801 and continuous opening 812 are arranged near the ground.

In a further embodiment of an optical liquid sensor it is provided that the emitter 800 directs the electromagnetic radiation 811 towards a reflecting element 810, for example a mirror. Fig. 6b shows a schematic representation of such a sensor element with an optical liquid sensor. The reflecting element 810 is designed as a mirror and lies in the beam path of the emitter 800, being slightly inclined to it. The electromagnetic radiation 811 can thereby reflected and directed towards the light sensor 801, where it can be detected.

The reflective element 810 is arranged in the container 300 at a position at which incoming fluid can collect. Fig. 6c shows a schematic representation of an optical liquid sensor with fluid present, which is marked with the reference number 820. The mirror 810 is covered with fluid 820 so that the electromagnetic radiation 811 impinges on the fluid 820. The incident electromagnetic radiation 811 is scattered and/or reflected on the surface of the fluid 820, so that less or no radiation 811 reaches the light sensor 801. This deviation can be detected and transmitted to the switching unit as a corresponding signal.

Claims

Patent claims

1 . Braking device (100) as part of a braking system, in particular for a motor vehicle, comprising a container (300) with a cavity, a hydraulic block (200) with a pressure supply device (202), and an electronic brake control device (311, 321), which is used to control the Pressure provision device (202) is set up, wherein the electronic brake control device (311, 321) is arranged in the container (300), at least one sensor element (400) being provided, which is designed to detect a fluid, and wherein the sensor element (400) is arranged in the container (300) or in the hydraulic block (200).

2. Braking device (100) according to one of the preceding claims, characterized in that the container (300) or the hydraulic block (200) comprise a bottom with a depression which defines the lowest point in the operating state, at least one bead preferably being provided on the bottom is, which is oriented towards the depression.

3. Braking device (100) according to one of the preceding claims, characterized in that the sensor element is designed to detect the presence or occurrence of a fluid.

4. Braking device (100) according to one of the preceding claims, characterized in that the hydraulic block (200) comprises valves (206, 216, 218) which are connected to the pressure supply device (202). Braking device (100) according to one of the preceding claims, characterized in that the at least one sensor element (400) is arranged near the ground, preferably in the area of the depression and particularly preferably within the depression. Braking device (100) according to one of the preceding claims, characterized in that at least two or more sensor elements (400) are provided, which are arranged spaced apart from one another in the vertical direction. Braking device (100) according to one of the preceding claims, characterized in that the container (300) is designed in two parts, with an intermediate wall (301) separating a first and a second partial volume (312, 322) from one another, and with a first brake control device (311 ) is arranged in the first sub-volume (312) and a second brake control device (321) in the second sub-volume (322). Brake device (100) according to one of the preceding claims, characterized in that the brake control device (311, 321) comprises at least one circuit board (500), the sensor element (400) being formed on the circuit board (500) or as part of the circuit board (500). is. Braking device (100) according to the preceding claim, characterized in that the at least one sensor element (400) is arranged on a section (501) of the circuit board (500) which points towards the ground during operation, this section (501) of the circuit board pointing towards the ground (500) is preferably free of other electronic or other components (502). Braking device (100) according to one of the two preceding claims, characterized in that the circuit board (500) comprises a projection on the edge pointing towards the ground during operation, the at least one sensor element (400) being at least partially arranged on this projection, the Projection with the sensor element (400) preferably at least is arranged in sections in the depression and particularly preferably projects into the depression. Braking device (100) according to one of the three preceding claims, characterized in that the at least one sensor element (400) is designed as a conductivity sensor (510). Braking device (100) according to one of the preceding claims, characterized in that the at least one sensor element (400) comprises a pressure sensor (620) and a fluid-sensitive element (600), wherein the fluid-sensitive element (600) comprises a material, wherein the fluid-sensitive element (600) can expand upon contact with fluid. Braking device (100) according to one of the preceding claims, characterized in that the at least one sensor element (400) is a fluid-sensitive element (601), preferably an electrically conductive fluid-sensitive element (601), with an electrical contact (611, 612 ), wherein the fluid-sensitive element (601) can contract or dissolve upon contact with fluid. Braking device (100) according to one of the preceding claims, characterized in that the at least one sensor element (400) comprises a floating body (700), wherein the floating body (700) is arranged to be movable in the vertical direction, and wherein the floating body (700) is designed for this purpose is to send an electrical signal to the switching unit when reaching or leaving a certain position. Braking device (100) according to the preceding claim, characterized in that the at least one floating body (700) is arranged in the hydraulic block (200). Braking device (100) according to one of the preceding claims, characterized in that the at least one sensor element (400) as optical liquid sensor is designed, comprising an emitter (800), which is set up to emit electromagnetic radiation during operation, and a light sensor (801), which is designed to detect this electromagnetic radiation (811), and wherein the light sensor (801) in Beam direction of the emitter (800) is arranged. Braking device (100) according to one of the preceding claims, characterized in that the hydraulic block (200) comprises a through hole (802) through which the electromagnetic radiation (811) of the light sensor (801) can be conducted during operation. Braking device (100) according to the preceding claim, characterized in that a reflecting element (810), in particular a mirror, is provided, which is preferably in the beam path of the emitter (800) at the bottom of the container (300) or the hydraulic block (200). in the sink, is arranged and can redirect light from the emitter (800) to the light sensor (801) during operation. Method for operating a braking system for a vehicle, in particular a service braking system, comprising at least one braking device (100) according to one of the preceding claims.